Precaution

A step taken beforehand to reduce the chance or impact of harm.

Reach for it when naming a preventive action chosen in response to a credible risk

As a precaution, the guide checked every headlamp before sunset.

• playful

  belt and braces

  for deliberately redundant protection in informal British usage

  not when This idiom can suggest overcaution and will be unfamiliar to some readers.

• everyday

  safety step

  when instructions need plain, immediately understandable language

  not when Safety step narrows the purpose to physical safety and sounds procedural.

• professional

  contingency

  if the measure is a fallback prepared for a possible event

  not when A contingency responds after a problem occurs, whereas a precaution may prevent it.

• professional

  preventive measure

  for a planned action intended to stop a problem arising

  not when Preventive measure is precise but heavier than precaution in ordinary speech.

• professional

  safeguard

  when an enduring measure protects people or systems

  not when A safeguard may remain in place permanently rather than address one occasion.

• formal

  foresight

  when good anticipation itself deserves praise

  not when Foresight is a quality of judgment, not the action produced by it.

• literary

  insurance

  for an extra provision that limits loss if events go wrong

  not when Readers may mistake this figurative use of insurance for a financial policy.

• recklessness
• neglect
• improvidence

• sensible precaution

  Bringing a paper map was a sensible precaution beyond carrying a phone.

• extra precaution

  The laboratory added an extra precaution during the power interruption.

• take a precaution

  Take a precaution now by labeling the backup valve clearly.